Watch crown



Jan. 6, 1959 R. PFlsTERER WATCH CROWN Original Filed Aug. 17, 1954 /NVEN raz- /P/CHARD PF/STERER BY CMM/1 i A TTOR/VEKS United States Patent@nice Patented Jan. 6, 1959 WATCH CROWN Richard Psterer, Pforzheim,Germany Original application August 17, 1954, Serial No. 450,345, nowPatent No. 2,849,854, dated September 2, 1958. Divided and thisapplication April 10, 1957, Serial No. 657,698

7 Claims. (Cl. 58-90) The present invention relates to a crown forwristwatches and pocket-watches which are provided with an elastically-or resiliently suspended watch-work.

This application is a division of the application filed by same namedinventor, filed August 17, 1954 and having a Ser. No. 450,345, PatentNo. 2,849,854.

It is already known to avoid the strain on the winding shaft through theprovision of a coupling part between the crown and the undividedwinding-shaft, whereby the coupling part (which is rigidly connected tothe winding shaft) nutatably rests against a spring. But crowns of thisknown type are not watertight, and can not be made watertight withoutserious disadvantages.

Contrary to this, the crown which the invention proposes to employ is sodivised that the spring presses the coupling part (which lis rigidlysecured to the windingshaft) onto the packing of the crown and therebyrenders the crown watertight.

For this purpose, the coupling part (which is rigidly secured to thewinding-shaft) is provided with a projecting rounded portion which restsin point-like fashion against a spring-plate or rubber-plate supportedin the crown only with marginal portions. In this way an always uniformall-round pressure is constantly exerted on the packing. The pressureupon the packing is preferably exerted by a flange pressed by the springdown upon the shoulder of the crown which, according to the invention,is formed by a packing ring secured in its position within the crown byan outer metal ring.

Additional features and advantages of the invention will be understoodfrom a consideration Iof the following detailed description taken inconnection with the accompanying drawings, forming a part of thisspecification and in which several embodiments of the invention havevbeen shown by way of example.

In the drawings Fig. 1 is a bottom plan View of the crown of awatertight watch seen in the direction of the arrow I of Fig. 2;

Fig. 2 is a central vertical section of the crown on line II-II of Fig.1;

Fig. 3 is a side-view, partly in section, of the crown mounted on thetube, on line IIl--III of Fig. l.

Referring now to the drawings in detail, a specific embodiment of thisinvention will now be described.

Screwed onto the winding-shaft 2 (Fig. 3) is the coupling 3. Thecoupling 3 has a flange 14 and a rounded portion 4 by means of which itis enable to nutate or reel on the spring plate 5 positioned above it inthe crown 6. The spring-plate Sis pretensioned and urges the flange 14of the coupling 3 against the shoulder or collar 12 of the crown 6.Arranged in the crown 6 beneath the spring-plate 5 is the ring 7provided with drivers 8 (see Fig. 2). To these drivers 8 correspondnotches 9 provided in the flange 14 Iof the coupling 3. There is so muchclearance between the notches 9 and the drivers 8 (see Fig. 1) that themovability of the coupling with respect to the spring-plate 5 is notinterfered with. The tube 10 of the watch extends into the gap 11between the coupling and crown (see Fig. 12). The annular shoulder orcollar 12 consists in the embodiment illustrated in the drawings ofelastic material (rubber). It simultaneously serves as packing ring, andis secured in its position in the crown by means of the ring 13.

However, I wish to say that the invention is not confined to any strictconformity with the showing of the drawings, but may be changed ormodified, so long as such changes or modifications will mark no materialdeparture from the salient features of the invention as expressed in theappendant claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A crown for a watertight watch of the type having, an undividedwinding-shaft surrounded by a tube; said crown being provided with aninner collar of packing material and a resilient plate above saidpacking collar which collar surrounds the Outer end of saidwinding-shaft and said tube, and a coupling part rigidly secured to theouter end of the winding-shaft and suitably shaped to overlap saidpacking collar and nutatably resting against said resilient platepressed by said resilient plate against said packing collar.

2. A crown for a watertight watch of the type having an undividedwinding-shaft surrounded by a tube; said crown being provided with aninner collar of packing ma terial and a rubber plate above said packingcollar which collar surrounds the outer end of said winding-shaft andtube, and a coupling part rigidly secured to the outer end of thewinding-shaft and suitably shaped to overlap said packing collar andnutatably resting against said rubber plate pressed by said rubber plateagainst said pack-ingy collar.

3. A crown for a watertight watch as per claim 1, in which said springis of the plate-spring type having its marginal portions secured to thewall of said crown above said coupling part; and in which said couplingpart is formed with an upwardly projecting rounded portion resting inpoint-like fashion against said plate-spring.

4. A crown for a watertight watch as per claim l, in which said couplingpart is provided with a laterally projecting flange overlapping saidpacking collar and pressed by said resilient plate against said packingcollar.

5. A crown for a watertight watch as per claim 1, including a metal ringsuitably arranged to secure said collar of packing material within saidcrown.

6. A crown for a watertight watch as per claim 1, in which said couplingpart is provided with a laterally projecting circular flange overlappingsaid packing collar and pressing said packing collar through thepressure exerted by said resilient plate against said tube.

7. A crown for a watertight watch-case having an elastically supportedring and watch-work therein and comprising a tube provided on saidwatch-case, an undivided winding shaft mounted unelastically in saidwatch-case and extending with play through said tube to the outside ofsaid watch-case; said crown mounted on said watchcase over said tube,water-tight packing means between said crown and said watch-case, springmeans inside said crown, and a coupling member rigidly attached to theend of said winding shaft inside said crown, said coupling memberbearing nutatably against said spring means inside said crown so as topermit said winding shaft to follow freely the displacements of saidelastically supported supporting ring and watch-work relative to saidwatch-case.

References Cited in the file of this patent FOREIGN PATENTS 434,651Great Britain Sept. 5, 1935 264,359 Switzerland Jan. 3, 1950 273,735Switzerland June l, 1951 1,029,191 France Mar. 4, 1953

